A calibration device which can calibrate angular rates of the two-axis position and rate rotary table is designed in this paper,and it is composed of circular grating, reading head, subdivision circuit, signal collection system and special calibration fixture.A portal frame with sliding rail and two reading heads is designed to eliminate the fix eccentricity error of circular grating ring. The morie fringes subdividing technology is used in the design of the signal collection and processing circuit, which reduces the error of the grating measurement greatly. It also designs a special calibration fixture with tunable dabber, which can simplify the installation and improve the efficiency of the calibration.?